Reactions of ruthenium triphenylphosphine complexes with diazadienes. Part 3. Preparation, characterization, X-ray crystal structure, and reactivity of a formally ruthenium(0) tris(α-di-imine) complex

Abstract

The reaction between [RuH₂(PPh₃)₄] or [RuH(C₆H₄PPh₂)(PPh₃)₂(C₂H₄)] and 3 equivalents of the α-di-imine p-MeOC₆H₄NCHCHNC₆H₄OMe-p(L) produces black crystalline [RuL₃]. This complex is diamagnetic below –10 °C and becomes paramagnetic at higher temperature. The X-ray crystal structure and u.v. spectra show that the three ligands are equivalent. The complex can be considered as containing 20-electron ruthenium(0). It is rapidly oxidized by molecular oxygen to [RuL₃]²⁺. Crystals of [RuL₃]·C₆H₅CH₃ are triclinic, space group P, with a= 14.269(2), b= 24.999(2), c= 13.967(2)Å, α= 92.04(1), β= 95.01(1), γ= 104.33(1)°, and Z= 4. The structure was refined using 3 867 ‘observed’ reflections to a final R value of 0.109.